(1) Field of the Invention
This invention relates to a means of mass production and formulation of inoculum of microorganisms.
(2) Description of the Prior Art
The merits for using plant pathogens to control weeds in annual crops have been discussed previously for two Colletotrichum spp.(Daniel, et al., U.S. Pat. No. 3,849,104 and Templeton, U.S. Pat. No. 3,999,973). The anthracnose fungus Colletotrichum gloeosporioides has been used to control the weed northern jointvetch, and other strain of this fungus has been used to control winged waterprimrose. Colletotrichum malvarum has been used to control prickly sida. Pathogens have been combined to control several target weeds at once. In other work the fungus Alternaria macrospora (American Type Culture Collection No. 42770) has been used to control spurred anoda (H. L. Walker, 1981. Weed Science, Vol. 29, pp. 505-507). Fusarium lateritium has been proposed as a biocontrol agent for spurred anoda, prickly sida, and velvetleaf (H. L. Walker, 1981. Weed Science 29:629-631 and U.S. Pat. No. 4,419,120. Alternaria cassiae has been used to control sicklepod, coffee senna, and showy crotalaria (H. L. Walker, 1982. Plant Disease 66:426-428 and U.S. Pat. No. 4,390,360.
The effective use of pathogens as microbial herbicides is dependent upon the mass production of inoculum so that periodic applications can be made to the target weeds. Formulation and application methods often are of paramount importance in determining the effectiveness of certain pathogens. Previously reported results indicate that granular formulations of some pathogens have potential as inoculum for weed control in row crop environments (H. L. Walker, 1981. Weed Science 29:342-345); however, the vermiculite carrier utilized in these formulations has the undesirable characteristics of bulkiness, nonuniformity in size, and the granules are easily washed away by rainfall.
The use of alginate gel technology to formulate agricultural products, pesticides, and food items has been disclosed. For example, U.S. Pat. No. 4,053,627 describes the use of alginate gel discs for mosquito control, U.S. Pat. No. 3,649,239 discloses fertilizer compositions, and U.S. Pat. No. 2,441,729 teaches the use of alginate gels as insecticidal as well as candy jellies. In addition, Connick, Jr., U.S. Pat. Nos. 4,401,456 and 4,400,391 disclose processes for preparing alginate gel beads containing bioactive materials. None of the prior art teaches the use of living fungi as an active material incorporated in an alginate matrix.